Peripheral devices are commonly connected to computing devices to extend the functionality of the computing devices. Peripheral devices include point-of-sale (POS) devices, such as cash registers, handheld bar code scanners, and other types of POS devices. Some types of peripheral devices are connected to a serial bus of a computing device. For example, the serial bus may be an RS-485 serial bus, an RS-423 serial bus, an RS-422 serial bus, or an RS-232 serial bus.